Improvement in potances for watches



C. V. WOE'RD. Potanoe for Watch.

Patented Jan. 22,1878.

Fig. 1.

In which .yw,

UNITED STATES PATENT OFFICE.

CHARLES V. W'OERD, OF WALTHAM, MASSACHUSETTS, ASSIGNOR TO AMERICAN WATCH COMPANY, OF SAME PLACE.

IMPROVEMENT IN POTANCES FOR WATCHES.

Specification forming part of Letters Patent No. 199,392, dated January 22, 1878; application filed December 7, 1877.

To all whom it may concern:

Be it known that I, CHARLES V. Wonnn, of Waltham, in the county of Middlesex and State of Massachusetts, have invented a new and useful Improvement in Potances for Watches, which improvement is fully set forth in the following specification, reference being had to the accompanying drawings, in which- Figure 1 represents a planview of top plate with potance inserted. Fig. 2 is a vertical section of the same on the line m a. Fig. 3 is a vertical section, showing top plate inserted into potance.

The object of my invention refers to the manner of attaching potances for watches to the top plate.

Potances, as heretofore made, consist of an offset piece attached to the under side of the top plate by one or more screws and steadypins, in such a manner that a space is left open between the plate and the lower portion of the potance, which contains the jewelstep for balance-staff, for the purpose of admitting the fork to the roller-pin.

The objection to this mode of attachment and form is insecurity of position and exposure to disarrangement by the steady-pins being liable to become loosened or bent. Consideration of the great sensitiveness of the balance, and h ow much an imperceptible change of position of step afi'ects and disturbs the motion of the same, induces me to produce a potance which is not exposed to these objections, but which is firmly and unalterably attached to the top plate, and which cannot be disturbed or disarranged; and my invention consists in a potance of a hollow form, with bottom containing the jewel for balance-staff,

a portion of the shell cut open to admit of the working of the fork, roller, and roller-pin, and its upper portion either wholly or partly inserted into the top plate, or the latter partly projecting into the potance and firmly secured thereto, thus securing the potance firmly to the top plate without the application of steady pins.

Referring to the drawings, Figs. 1 and 2, (0 represents the top plate; I), the potance, of which 0 is the portion to be staked or riveted; (Z, the annular shoulder, coiuitersunk into the plate a; e, the bodyportion, showing the openin g f,- and g, the bottom, with the aperture h for receiving the jewel-step.

In Fig. 3 the top plate projects partly into the potance, in which i is aprojection on plate a 7a, a recess in potance, into whichi is closely fitted, thus keeping the potance always in the most exact position.

I do not confine myself to aparticular form, whether cylindrical or otherwise, nor to the fastening of the potance by riveting or staking, as it may be screwed into the top plate or held by two or more screws; but

What I claim as my invention is The hollow potance b, the portion 0 d of which is partly or wholly inserted into the top plate a, or the top plate a partly projecting into the potance Z thus securing the correct position of the latter, constructed substantially in the manner and for the purpose as above described.

CHAS. V. \VOERD.

Witnesses WM. H. WRENN, M. WILDE. 

